This application is for a five-year extension of funding for the Pediatric Eye Disease Investigator Group (PEDIG) for the PEDIG Coordinating Center (CC). In tandem with this application, a separate application is being submitted for the PEDIG Chair's Office. PEDIG was formed to conduct clinical research in strabismus, amblyopia, and other eye disorders that affect children. The rationale for a network such as PEDIG is that efficiency is enhanced and costs reduced by having a single ongoing infrastructure that is able to conduct multiple concurrent and consecutive studies. The start-up time to implement a new trial from the inception of the concept for the trial to initiation of recruitment is greatly shortened. The primary focus of PEDIG involves studies that can be conducted through simple protocols with limited data collection and implemented by both university-based and community-based pediatric eye care practitioners as part of their routine practice. PEDIG's accomplishments were recognized by the Inventory and Evaluation of Clinical Research Networks (IECRN) as a part of the NIH's roadmap initiative. During its funding period since 1997, the network has conducted or is currently conducting two protocols in esotropia, 12 protocols in amblyopia, two protocols in nasolacrimal duct obstruction, and one protocol in myopia. In addition, several pilot studies have been conducted. By the time the funding specified in this application begins, it is expected that four new amblyopia protocols will have begun as well as a protocol in juvenile idiopathic arthritis and a protocol to determine normal corneal thickness in the pediatric population. Other accomplishments of the network include development of a standardized, computerized visual acuity testing protocol for children, a quality of life measurement instrument for treatment of amblyopia, and a quality of life instrument for nasolacrimal duct obstruction. The specific PEDIG aims for the next funding period include: (1) complete 6 protocols that are expected to be in progress at the time the funding period begins, (2) initiate approximately 10 new protocols in pediatric eye disorders, (3) continue to expand the PEDIG network by soliciting the participation of new investigators and new sites, and (4) continue to educate the pediatric ophthalmology and optometry communities on the principles of clinical trials and train selected pediatric ophthalmologists and optometrists to be leaders in clinical trials. The Coordinating Center plays a key role in the Network's ability to achieve these goals.